Glow-in-the-dark pigs are part of radiant green menagerie

A glow-in-the-dark pig

Transgenic piglets glow in the dark in a Chinese lab.

Transgenic piglets glow in the dark in a Chinese lab.

Deborah Netburn

Ready yourself for the real-life glowing green menagerie.

Ten little piggies that glow in the dark have been created by scientists at the South China Agricultural University. (See the video above.) A sheep that glows green under a black light will soon be announced by researchers in Turkey, and that same Turkish team has already created glow-in-the-dark bunnies.

By the light of day these animals all look normal. But turn off the lights and hit them with a black light and parts of their bodies glow fluorescent green.

The glowing mammals were created when scientists inserted a foreign gene into the animals' DNA. In a process called active transgenesis, the scientists removed embryos from pregnant females and injected each one with a jellyfish gene that creates a glow-in-the-dark protein. Then the embryos were put back in the mother.

Not every embryo picked up the gene. With the pigs for example, 25 embryos were injected with the glowing-protein gene, but just 10 animals were born that actually glow.

This is not the first time that scientists have created glow-in-the-dark pigs, said Stefan Moisyadi of the University of Hawaii at Manoa, who worked with Chinese scientists Zhenfang Wu and Zicong Li. But he said their efforts represent the most efficient production of glow-in-the-dark pigs yet.

"In the past, scientists would throw the DNA in the embryo and hope that it would take, but it was a very hit-or-miss deal, and just 2% of the micro-manipulated eggs were transgenic," Moisyadi told the Los Angeles Times. "But we came in with this active approach, embedding the jellyfish gene in a plasmid that contains an insertion gene, and it is a huge improvement."

The end goal here is not to create trippy animals that look cool under black lights, but rather to show that the active transgenic technique works and can be done efficiently. The green glow is just a marker that the animals have picked up the jellyfish gene.

Eventually, Moisyadi believes genes could be inserted into the animals' DNA that would cause them to create proteins that would be useful for medicines, and that could be extracted through their milk.

One more note: In the video above, you will hear the pigs squealing uncomfortably at the 50-second mark. According to a news release issued by the University of Hawaii, the pigs are not being hurt; they are scared of the dark and don't like being held down in that plastic tub.

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